510 CYCADOPHYTAN FRONDS [CH. 



Wealden period, a period very closely linked in the character 

 of the vegetation with the preceding Jurassic floras, there appears 

 to have been a relatively sudden decrease in the number of members 

 of the Cycadophyta: the decline in the fortunes of Cycadean 

 plants is coincident with the rise and remarkably rapid extension 

 of the Angiosperms. From Middle and Upper Cretaceous and 

 from Tertiary beds very few Cycadean remains have been obtained 

 and many of them are represented by fragmentary fossils that 

 afford no definite evidence of affinity to recent genera. The 

 antiquity of the Cycadales, that is the section represented by 

 existing Cycads, cannot be determined ; but it would seem probable 

 that if the Cycads apart from the Bennettitales existed in Jurassic 

 and Lower Cretaceous floras they occupied a very subordinate 

 position in comparison with the extinct Bennettitales. There are 

 no data pointing to any widespread occurrence of the Cycadales 

 in the Northern Hemisphere in Tertiary times at all comparable 

 with the geographical range of Tertiary ancestors of the solitary 

 survivor of the Ginkgoales. 



The following records of Tertiary Cycadean fronds illustrate 

 the paucity of the records. Reference has already been made to 

 Encephalartos Gorceixianus Sap. of Miocene age, a species that 

 has no claim to be regarded as an example of the recent South 

 African genus. The specimen described by Saporta and Marion 

 as ? Zamites palaeocenicus 1 from the Eocene of Gelinden is too 

 imperfect to serve as a trustworthy record. A more satis- 

 factory species, similar in habit to Zamites gigas, is that on which 

 Saporta founded the species Zamites epibius 2 from Lower Miocene 

 beds at Bonnieux (Vaucluse), France. Another Tertiary species 

 is mentioned by Krasser 3 from Pliocene strata in Brazil as Zamia 

 praecedens Krass. ex Ett. MS. Ettingshausen has described a 

 Tertiary species from New South Wales, either Lower Miocene 

 or Upper Eocene in age, as Anomozamites Muelleri*, characterised 

 by truncate segments with simple veins and set obliquely to the 

 rachis. 



While certain form-genera of fronds can only be referred to 



1 Saporta and Marion (78) PL I. figs. 4, 5. 



2 Ibid. (85) fig. 61, A, p. 116. 3 Krasser (03) p. 852. 

 4 Ettingshausen (86) PL vm. figs. 1921; (88) PL vra. figs. 1921. 



